Telephone system



March 21, 1933- N. H. SAUNDERS TELEPHONE SYSTEM Original Filed Sept. 8, 1930 Narman H.5EUI1dEIE Patented Mar. 21, 1933 umrsn 5mm rem orrice NORMAN "II-SAUNDERS, CEIGAGG, HYDE 0181, 018 MESH-E 4SSIGNQEENTS,

' ASSOCIATBD ELECTRIC LAJORAIPOB R, 189;; 'CJ'IIOQGO, *I'LLI'NOIB, A 001111)- TION *OFDELAWABE :Dniginal application fllullepteuhnr 5B,

Lllhe present invention relates-in generalto telephonesystems, but is concernedmore particularly with automatic telephone systems employing automatic selector and connector ..SWitches ofthe stepYby-step type. The main object ,of the inventionis theqprovisioniof improved-selector andconnectorswitch circuits which perform all the required ,functions of such switches in an improved and .more reliable manner.

A particular feature of the selector. circuit is the noveltesting and steppingm'rangement for controlling the automatic rotary move- .ment of the switch.

A particular feature of the connector circuit-lies in the novel changeover scheme in whichthe switch is caused to take anauto- :matic rotary step to performlthe changeover from the directive vertical movement -to.,-the directive rotary movement.

This application is a division of my copending application Serial No. 480,313, filed September 8, 1930, for improvements in telephone systems. The features Qlaimed in'this divisional application relate to the new and improved connector switch.

A complete understanding of the aboveaud 4 other features of the 1 invention may lbestibe had from-the followin' specification when .read in-connectionwit -te accompanying drawing, comprising one :figure only, =-which shows, bymeains of: the usual schema-tic diagram, atelephone system; employing-the i nproved selector-and connectorswithes of the present invention.

Referring to :the drawing,T and P1 ,rep- -resent-a calling and .a called ,subscriber?s station, respectively, of an autcmatic telephone system. The line comprisingconductors 46 and 47 from station Tterminateslatzthevtelephone exchange in a rotary ilineswitch indicated by :the rectangle designatedtlus, and

having wipers 4,5, audit The subseribers line is accessible as a called/station Efrom contactor banks over conductors 1, 2,and-i3. "The selector S is the improved selector of'the present-invention and is accessible in the banks of rotarylineswitches such mama in :tu-rn hasaccess to the improved connector :witbh :C-o'veriback contacts 50,"5'1,and 52. conrnnmgonn SYSTE M r1880, flotial iotwlfl- :Iliuldqd rand ithislapplioation filed Inner,

"Mil. :Snial Io. 5fli5m.

necta aC isio of a numb r of similar .conenectors a d h s a ss i ba k t Su scribers stations, such as T1,, QVer bank WWQQ a 1 81, an 09- Co du tors 112 ,1 13,and;-1 1A extend-to a rotary line- 1& switch, suchi as LS- A dcta lsd cxplan t n 10 th op rat n lofthe improved s l c o and o nec q ci cnits will ynow g cn- Q Yth -PU PQ e it mill bea SUm dthatL-thesubscriber at station 1454) '(I sets ,up a connection ate the subscriber at s ation T5 whos t eph num 5 B $P I t rthe e ova Qfith :recc e e station 1, therotary lineswitchLS is setin wa n oi e c a id c tr k in th usua ma nc M w ll b fls umed tha he unk ie tcndi igi rth se cto w chj isth firs dl 'unk.a ilab c d ha Me sei ed fline fic LSh cr \WiPQE 4, fiend: 6-

A s n as the lin i :c through-to th select-Q sni h (Salin relay 1 10f; th isel cte 9P t iD Q r h (calling; loop in th -followmg circuitbat ry, upper ndilgi 0f1' cl y 9, res ing iconta iof arm ure -27 nd sai ec atureebank Qatac ng-eg d -:by wiper A o i inesw ch an said wiper, 'line cancli ctori ttcall ng loop at tation T, lin c0nzducto .7, pe fi landv bank-contact0 :r ztarya line wi i hilis., armature26 and its restnigicontactfi ower -Wlndlng0f relay ,10,, norr39 imall-y-closedieleventh rotary-step contact 34, zt iground through the dialqtone equipment ,overrconduetor 43. jgBelay 10operates,and,at armgtnre ll and its frontrcontact closes a ti ouitefrontground, re stance :88, armature i111 its front contact, winding, of release gtklfiyflg ,2 testing contact of rotary off-normal ,gpring 37:1And said spring-winding of relay ,,20,,.to battery. Belay (operates lIht-hlS ciriel itahutirelay F does-not operate duetosthe thighsresistanceofrthe release relay-l5. A re- -siatancer38is provided so that [relay 20 does 'cROt-QpQl'fltG at the instant whenthe three springs (oflinetrelay 1O are all .inrcontaet during the; energization of said relay.

iBelay 15 in operating at armature :19 and rfront contact .groundsthe release trunk iconcluctnrz'f ;:to.- hold lZlIBllIlBSWllJChLS in 0perated condition and also; to: busy: the cal-ling dine in; the {banks of connector switches over conductor 2. At armature l7 and its front contact, it prepares an impulsing circuit to the vertical magnet 22, and at armature 16 and itsfront contact it prepares a further point in the impulsing circuit of the vertical magnet 22 and prepares an operating circuit for the series relay 20. At armature 18 and its back contact, relay 15 opens a point in the circuit of release magnet 39, and at its working contact prepares a point in the circuit of the rotary magnet 41.

WVhen the subscriber at station T hears the dial tone supplied .over conductor 43 through ture 30 and said armature, armature 16 and its working contact, normally closed springs controlled by armature 11 of line relay 10,

working contact of armature 17 and said armature, through the winding of vertical n'iagnet 22, to battery. A multiple circuit extends over the resting contact of rotary offnormal spring 37 and said spring, through the winding of series relay 20, to battery. Relay 20 operates at the first impulse, and at armature 21 and its resting contact opens.

a oint in the circuit of rotary magnet 41.

ertical magnet 22 responds to the impulses and raises the shaft and switch wipers of the selector to a point opposite the fifth level or the banks. At the first vertical step, vertical off-normal springs 36are closed, preparing a circuit for the rotary magnet 41. -Se ries relay 20 is slow to release due to the current through its winding in series with release relay 15. This current is not sufiicient to hold relay 20 operated but is suflicient to make the relayslow to release so that it remains operated during the impulse series, maintaining the circuit of rotary magnet 41 open at armature 21 and its resting contact. At' the end of the series of impulses, line relay 10 remains energized, and, after an interval, series relay 2O releases and closes the circuit or rotary magnet 41 at armature 21 and its resting contact. The rotary magnet energizes and steps the switch wipers 31, 32,

and 33 into engagement with the first set of bank contacts in the fifth level of the selector ba'nle At the first rotary step, rotary off-normal spring 37 is operated and engages its working contact, thereby completing a circuit from battery, winding of relay 20, ro-

tary off-normal spring 37 and its working contact,.interrupter contacts 42 of the rotary magnet, resting contact of armature 29 and said armature, to test wiper 32 or the selector switch. The operation now depends upon again opens the circuit of relay 20. Relay 20 releases, and at armature 21 and its resting ,contactagain completes the energizing circuit of rotary magnet 41 which operates and steps the switchwipersinto cngagementwith the second set of bank contacts. action between the rotary magnet 41 and the stepping relay 20 continues as long as a groundpotential is encountered on the bank contacts engaged .by the test wiper 32.

This inter- Each time the rotary magnet energizes and closes its interrupter contacts 42, a circult is completed from ground, armature 19 and'its'working contact,'eleventh rotary-step springs 23, winding of switching relay 25, interrupter contacts 42 0f the rotary magnet, working contact of rotary off-normal'spring 37 and said spring, winding of' relay 20, to battery. As long as the test wiper 32 is engaging a grounded bankcontact. switching relay 25 is short circuited by ground oy'er wiper 32, armature 29 and its resting contact,

to the lower terminal of switching relay 25.

The switching relay 2:) is thereby prevented 'from'operating, and the groundon the test wiper brings about the operation of relay 2() to again cause the switch to take another rotary step.

In case all of the trunks accessible in the fifth level of the selector banks are busy, the switch is automatically rotated to its eleventh rotary position and the eleventh rotary step springs are operated. At spring 23 and its resting contact, the circuit of switching relay 25 is opened so that this relay cannot operate. At contacts 35, busy tone over conductor44 is connected'to the lower winding of relay A to replacethe'dial tone. When the calling subscriber hears the busy tone, he knows that the connection cannot be completed at this time, and he replaces his receiver to release the connection as will bedescribed later.

" It will now be assumed that the connector C, accessible over bank contacts 50, 51, and 52, is idle when tested by the selector switch S. In this case, there is no ground on test wiper32 and the switching relay 25 and the stepping reiay20 energizes in series over the following circuit: from ground, armature19 and its working contact, eleventh rotary-step spring 23, winding of switching relay 25, interrupter contacts 42 of the rotary magnet 41, working contact of rotary off-normal spring 37 and said spring, winding of relay 20, to battery. .Relay 25, zit-armature 28 and its workingcont'act, closes a locking circuit for itself in series with relay 20 independent operatedthe connector vertically to a position opposite'the sixth level of bank contacts, relay 80 deenergize s and at the normallyclosed springs controlled by armature 81 completes a locking circuit for relay 75 extendiSO ing fromground on release trunk conductor 106, armature 76 and its working contact, interrupter, contacts 100 of rotary magnet 99, normally-closed springs controlled. by armature 81, resting contact of armature 89 and said armature, winding of relayf7 5, tobat- .tery. At armature 82and its working contact, relay 80 opens the impulsing circuit to the vertical magnet, and at armature 8,3 and its working contact opens the original ,energizing'circuit of relay 75, and at its resting contact completes .a circuit for the rotary magnet99 extending from ground, vertical off-normal spring 97 and its. working contact, armature 69 and its working contact, rotary off-normal spring 102 and its resting contact, armature. 83 and its resting contact, armature 78 and its working contact, winding ofrotarymagnet99, to battery. The rotary magnetenergizes and advances the switch wipers one step toward the bank contacts. The rotary off-normal spring 101 is operated by the first rotary step of the switch, :but the rotary oil-normal spring 102 is not operated until the, wipers are'brought into engagement with" the first setof bank contacts when they switch takes its second rotary step.

Rotary magnet 99, upon energizing, opens its interrupter contacts 100, thereby opening the locking. circuit of relay 75. Relay 75 releases, and at armature 76 and its working contact opens a further point in its locking circuit, at armature 77 and its'resting contact it closes a point in the impulsing circuit tothe rotary magnet 99, and at armature 78 and its working contact it opens a'point in the original energizing circuit of the rotary magnet. Rotary oif-normal spring 101, upon operating in response to the first rotary step of the switch, transfers the impulsing circuit from the vertical magnet 98m therotary magnet 99. Y

In response to the dialling of the final digit 7 of the called telephone number, line relay 60 releases seven times, thereby sending seven impulses to the rotary magnet 99 over the following circuit: from ground at the working contact of armature 68 and said armature, normally-closed springs controlled by armature 61,-armature 77 and its resting contact, armature 91 and its rest ng contact, rotary off-normal spring 101 and its working contact, winding of rotary magnet 99 to bat tary movement, rotary oil-normal spring 102 operates'and opensthe original energizing circuit of relay 7 5 and of rotary magnet 99.

Series relay 80 energizes .at the first impulse and remains operated throughout the impulse train in the manner previously described. At armature 83 and its working contact it again closes a point in the energizing circuit of relay 75, but this circuit is now open at the rotary off-normal spring 102. At armature 82 and its working contact, re-

lay 80 closes a point in the impulsing circuit independent of armature. 77 toprevent the opening of the impulsing circuit in case the busy relay 75 should energize while the switchwipcrs are passing over busy contacts. At armature 81 and its Working contact, relay 80 completes the testing circuit extending from test wiper 93, armature 81 and its working contact, resting contact of armature 89 and said armature, winding of busy relay 75,

winding of relay 75, to battery. At armature 7 7 and its resting contact, relay 75 opens a point in the nnpulsing circult, and at armature 76 and its working contact prepares a point in its locking circuit which is completed upon the release of relay 80. A short time after the cessation of the impulse train, relay 80releases and at the normally-closed springs controlled by armature 81 completes the previously-traced locking circuit for the busy'test relay 75. At -armature 82 and its working contact, relay 80 opens a second point in the impulsing circuit. Relay 75 at armature-7 9 and its-W rkin contact connects the busy tone to the lower talkingconductor, thereby informing the calling subscriber that the-desired called station isnot available at this time. The calling subscriber thereupon hangs up his receiver and releases the established connection in. amanner-to be hereinafter pointed out.

It will now be assumed that the called line is idle when the connector switch wipers are brought into engagement with bank contacts 107, 108, and 109. In thiscase, there is gize. When relay 80 releases a short time afterthe cessation of the impulse train, it completes an energizing circuit for the switching relay 85 extending from ground on release trunk conductor 106, armature 76 and its resting contact, lower winding of switching relay 85, resting contact of armature 81 ,no ground potential present upon the bank contact 108, and busy'relay 75 will not enermoan? and said armature, test wiper 93, bank contact 168, and thence over conductor'113, to-

resting contact it opens a point inthe ener-' giz-ing circuit of busy relay 75, at armature 88 and its working contact it connects ground to test wiper 93 to busy the line to other connectors such as C, and at armatnres 86 and 87 and their working, contacts itcompletes,

the ringing circuit extending from interru nergemrator over conductor 104, lower wimlingof ring-eut-oif relay 70, resting contact of armature 71 and said armature, working contact of armature 86 and said armature, wiper 92, bank contact 107, conductor 5 11.6 of the called line, through the bridged condenser and ringer at the substation T1, conductor 111 of the called line, bank contact 109, wiper 94, armature 87 and its work-.

ing contact, armature 7 2 and its resting contact, to ground. v

Rin 'h g current is sent out overthis circuit to signal the called linc,.and, when the called subscriber removes his receiver, a direct current bridge is closed across conductors 110 and 111 of the called line and ringcut-off relay 70 operates over the above-traced ringing circuit. At armature 73 and its working contact, it completes a locking circuit for itself extending from ground at ar mature 67 of relay 65. At armatures- 71 and 7 2- and their resting contacts, it disconnects the ringing circuit, and at the working contacts of these armatures'it completes the talking circuit to the called line. Backbridge relay energizes over the called loop responsive to the cnergization of ring-cut-ofi rein 7'0, and at armatures 5'6 and 57 and their wor ring contacts reverses the battery connection of line relay 60 to the calling line to 0 crate the calling subscribers mc'ter in t c usual manner.

When the conversation is completed and the called subscriber at'station'll hangs up his receiver, thebridge across the called line is opened and back'b'ridge relay 55 releases and restores the normal battery connections tothe calling line. 1 When the calling subscribe! at station T replaces his receiver, the circuit of line relay 603s opened and this relay accordingly dcenergizes. At armature 61 and its working contact, it opens the circuit of release relay 65, and at the normallyclosed springs controlled by this armature it short circuits the winding of the release relay to make it t relea A er an in;

tcrvah'relmy 65 releases and at armature 67 and its working contact opens the locking circuits of the ring-cut-ofi relay 70 and switching relay 85. At armature 66 and its working contact it removes ground from release trunk conductor 106 to bring about the release of the selector switch S. At armature 69 and its back contact, release relay 65 closes a circuit for the release magnet extcndingefrmn ground, vertical oil-normal spring 97 and its working contact, armature and its resting contact, release link spring 96 and its resting contact, winding of release magnet 95', to battery. I The release link and the manner in which it controls spring 96 is the same as disclosed in Patent No. 1,612,767, issued Dcccmbcr 28, 1926, to Clarence E. Lomax. When release magnet 95'energizes and brings about the release of the switch, the release link 115 locks the double dog (not shown) in an operated position until the switch shaft has returned to its normal position, and at the same time operates sprin 96. With spring 96 in its operated position, the ciredit of release magnet 95 is opened and the release ground is transferred to the slow alarm equipment over conductor 103. In casethe switch does not completely restore to normal, the slow alarm equipment (not shown) brings in an alarm to call attention tothe fact-that one of the connector switches has not properly released. When the cm:- ncctor shaft reaches its normal position, the vertical oil-normal s ring Wis opened, thereby removing grou from conductor 103 and from the slow-actil'lg alarm equipment. The releaselink is forced out of engagement with the double dog as soon as the connector has returned to normal and returns the spring 9 to its normal position, thereby again preparing the release circuit to the winding of release magnet 95. This special releasing arrangement does away with the continued encrgi'zation of the release magnet in case the switch, sticks off-normal and does not completely restore to its normal position. I "Theremoval of ground from release trunk conductor'iofi' upon the release of relav 65 opens the circuit of relays 20 and 25 of the selector'swit'ch S. Relay 20 in releasing at armature 21 and its resting contact closes a circuit to the release magnet/39 extending from ground, vertical off-normal spring 36 and its working contact, armature 21 and its resting' contact, armature 18 and its resting Contact, release link spring 40 and its resting contact, winding of release magnet 39, to battcry- Release magnet v39 energizes to bring about the release of the'selector switch and the release link 48 operates spring40 to transfer the release ground from the winding of the release magnet to the slow-acting alarm equipment over conductor 15- in the 5am 13 manner as pointed out in connection with the release of the connector switch C. As soon as selector switch S has returned to normal vertical off-normal spring 36 is operated, thereby removing ground from the slow-acting alarm equipment and release link spring 40 is returned to normal, thereby again preparing a circuit for release magnet 39. All apparatus used in the connection has nowbeen restored to its normal con dition. I 1' Having described the invention, what is thought to be new and is desired to have protected by Letters Patent will be pointed out in the appended claims. What is claimed is:

1. In an automatic switch having directive primany and secondary movements, a control circuit over which the primary opera tion of said switch is effected, a second control circuit over which the secondary operation of said switch is-cffected, and means au-. tomat-ically operative :at the end of the pri-' mary movement for causing said switch to ment, means responsive to the cessation of 35' the vertical movement for operating said switch one step in its rotary movement, and rotary off-normal springsoperated by said rotary step and effective to'efiect' the'changeover from said first to said second impulsing circuit. V 3. In a switch control circuit for'automatic switching devices having primary and secondary'movements, an impulsing. circuit over which impulses are transmitted to control the switch. in its two movements, said circuit terminating in two branches, means for operating said switch in. its'primary movement over the first of said branches,

7 means responsive to the cessation of said primary movement for causing said switch to take one step in its secondary movement, and meanseresponsive to said last means for transferring said impulsing circuit to the second of said branches.

4C. In a two-motion automatic switch, .a primary magnet and a secondary magnet, an impulsing circuit extending to said primary magnet, means for sending impulses 0 over said circuit to control said switch in its 6 primary movement, means responsive to the cessation of saidprimary movement for operating said switch one fstep in its secondary movement, and means responsive to said operation for transferring. said impulsing .circuit to said secondary magnet.

5. In a step-by-step connectorswitch hav I '6. In a connector switch having vertical and rotary movements, means for d1rect1vely operating said switch in its verticalmovement, a first and a second relay energized throughout said vertical movement, a locking circuit for said first relayclosed by the deenergization of said second relay at the termination of said vertical movement, a rotary magnet, and a circuit for'said rotary magnet including make contacts on said first relay and back contacts on said second relay.

7. In a connector switch having vertical and rotary movements, means for directively operating said switch in its vertical move ment, a first and a second relay energized throughout said vertical movement, a looking circuit for said first relay closed by the deenergization' of said second relay at the termination of said vertical movement, a 1'0- tary magnet, a circuit for said rotary magnet including make contacts on'said first relay and back contacts on said second relay, and interru titer contacts on saidrotary magnet for openingthc locking circuit ofsaid first relay 8. In an automatic switch having directive primary and secondary movements, means for operating said switch in its primary movement, means responsive to the cessation of said primary movement for automatically operating said switch in its secondary movement, and means responsive to said automatic secondary operation for effecting'thechangeover from the directive primary to the directive secondary movement.

9. In an automaticswitch having directive primary and secondary movements, means for directively moving saidswitch in its primary movement, means responsive to the cessation of said primary movement for causing an automatic movement of said switch, and means responsive to said automatic movement for preparing said switch for its directive secondarymovement.

10. In an automatic switchhaving primary and secondary movements, a control circuit ov er' which said switch is dijrectively controlled in its primary movement, a second control circuit over which said switch is directively' controlled in its secondary movement,'means for causing an automatic movement of 'saidfswitchatthe endof-the directive "primary movement, and means respon sive to-said automatic movement for eli'ecting the changeover from said first to said second control circuit.

11. In combination, an automatic switch, said switch having a progressively movable selecting element, a control circuit, primary operating means for said selecting element directively responsive to a selective control exercised. over said circuit, automatic means for moving said selecting element responsive to the cessation of said selective control, and secondary operating means for said selecting clement rendered responsive by the automatic movement of said selecting element to a second selective control exercised over said cireuit.

In Witness whereof, I hereunto subscribe my name this 26th day of June, A. D. 1931.

NORMAN H. SAUNDERS. 

